The Contribution of Changes of Intracelluar Potassium Ion Concentration to the Kinetics of Voltage-Dependent Potassium Current
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Voltage-dependent potassium channels (Kv channels) mediate the voltage-dependent potassium ionic current, contribute to the generation of the action potential and to the regulation of neuronal excitability. To date, a large number of studies of these ion channels have been carried out using the patch-clamp method in the whole-cell configuration. It is generally assumed that during the implementation of this method intracellular ion concentrations remain approximately constant due to the relatively rapid exchange of the content between the cytoplasm and the patch pipette. However, this assumption may be incorrect if the flow of ions through the membrane is large. It was demonstrated in this study that the large outward currents of potassium ions can lead to a decrease in their intracellular concentration even during the whole-cell patch-clamp recording. This phenomenon can accelerate the decay of the recorded voltage-dependent potassium currents and may consequently lead to the overestimation of the inactivation rate of voltage-dependent potassium channels.
Keywords:patch-clamp voltage-gated potassium channels intracellular potassium concentration
The work was carried out within the state assignment of the Ministry of Education and Science of Russia (project “Neurophysiological mechanisms of regulation of functions and their evolution”, theme no. AAAA A18-118012290372-0).
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Conflict of interests. The authors declare that they have no conflict of interest.
Statement on the welfare of animals. All experimental procedures followed the guidelines of the European Community Council Directive 86/609/EEC and were approved by the Animal Care and Use Committee of the Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences.
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